JP3629708B2 - Method for splitting an inflow of solid particulates into a partial flow and apparatus for performing this method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention relates to a method for dividing an inflow comprising solid particles according to claim 1 into a partial flow and to an apparatus for carrying out the method according to claim 5.
[0002]
[Prior art]
It is known to split an influent stream consisting of hot solid particles discharged from a fluidized bed reactor and separated from a smoke-gas stream in a cyclone into a partial stream. One partial stream is recycled directly to the fluidized bed reactor, and the other partial stream is directed back to the fluidized bed reactor via a heat exchanger (eg, moving bed cooler). In the heat exchanger, the partial stream diverted in this way is cooled to recover heat. The ratio of these two partial flows is adjusted by mechanical means such as flaps or valves. The temperature in the fluidized bed reactor can be effectively adjusted by adjusting the amount of solids that are diverted through the heat exchanger.
These mechanical means are exposed to high working temperatures and high mechanical stresses.
[0003]
[Problems to be solved by the invention]
The object on which the invention is based is to provide a method of the kind mentioned at the outset and an apparatus for carrying out said method which does not use complex mechanical means and is simple to maintain.
[0004]
[Means for Solving the Problems]
This object is achieved according to the invention by a method having the features of claim 1 and by an apparatus having the features of claim 5.
Preferred refinements of the method according to the invention and the device according to the invention form the object of the dependent claims.
[0005]
In the method according to the invention, the mechanical turning means for dividing the inflow is replaced by process-related means. This exempts the costs arising from the design and materials as well as the complicated maintenance work for the mechanical turning means.
The process according to the invention is simple and nevertheless allows an exact adjustment for the quantity ratio in the individual substreams. An apparatus according to the invention for carrying out the method is cost effective from a manufacturing and maintenance point of view.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The invention is explained in more detail below with reference to the drawings.
FIG. 1 illustrates an apparatus 1 that divides an inflow consisting of solid particulates indicated by arrows Z into two partial flows indicated by arrows T ₁ and T ₂ . The device 1 has a housing 2 that laterally delimits the turning space 4, and a vertical supply duct 3 opens into the housing 2 from above. The turning space 4 is closed from below by a bottom 5. The bottom 5 separates the turning space 4 from a three-part air chamber 7 and comprises a number of orifices 6 distributed regularly over the bottom (FIG. 3). Arrow F indicates the supply of gaseous fluidizing agent to the individual parts of the air chamber 7 connected to the turning space 4 via the orifice 6 in FIG.
[0007]
The turning space 4 is connected to the second outlet duct 11 for the first derivation duct 10, also of the second partial stream T ₂ for the first part stream T _1. Each lead-out duct 10 and 11 has a vertical part 10a and 11a which opens into the turning space 4 and is turned at the top to the parts 10b and 11b which are directed obliquely downward. There are turning edges 12 and 13 which in each case function as outflow edges at the transition points of these two parts 10a, 10b and 11a, 11b of the respective outlet ducts 10 and 11. Preferably, the turning edge 13 of the second outlet duct 11 is higher than the turning edge 12 of the first outlet duct 10, in other words, further forward in the direction of flow. In this exemplary embodiment, the diameter of the second outlet duct 11 is smaller than the diameter of the first outlet duct 10.
[0008]
It said second outlet duct 11 is provided with a device 15 for injecting a gaseous diluting agent into the second partial stream T _2. This device is a tubular lance 16 which is arranged on the housing wall 2a and protrudes horizontally through the vertical part 11a of the second outlet duct 11, which is particularly evident from FIGS. The tubular lance 16 is disposed in a lower region of the vertical portion 11 a of the second outlet duct 11 in the vicinity of the turning space 4. The lance 16 includes a number of radial orifices 17 disposed in the lower half of the lance wall 16a over a length corresponding to the diameter of the second outlet duct 11 (FIG. 5). In FIG. 4, the distribution of the orifice 17 along the length of the lance is indicated by vertical dashes (if this is not done, the distribution is not apparent from this view). As is clear from FIG. 5, the axis of the radial orifice 17 forms an angle α with the horizontal axis plane h of the lance 16. Said angle α is preferably in the range of 0 ° to 45 °. In the exemplary embodiment shown, the angle α is 15 °. At the same time, in each case, the two orifices 17 are arranged symmetrically with respect to the vertical axis plane v of the lance 16. The orifices 17 are regularly distributed over the length of the lance 16 that traverses through the second outlet duct 11.
The supply of gaseous diluent is symbolized in FIG.
[0009]
An inflow Z consisting of solid particles supplied from above through the supply duct 3 is fluidized from below in the turning space 4. The suspended solid particles are forcibly fed from the lower side to the upper side to the two lead-out ducts 10 and 11. The solid divided into the two partial streams T ₁ , T ₂ is raised through the vertical parts 10 a, 11 a of the outlet ducts 10, 11 under the action of a gaseous fluidizing agent F. Gaseous fluidizing agent is fed constantly and uniformly brought distributed over the bottom 5, when the diameter of the two outlet ducts 10 and 11 are the same, the same amount of solids the two partial flows T ₁ It is transported at the same speed by T _2. In the case of the ratio of the diameters of the two outlet ducts 10 and 11 shown in FIG. 1, more solids than the second outlet duct 11 are caused to flow into the first outlet duct 10 by the gaseous fluidizing agent. It is forcibly sent to. However, according to the present invention, the amount of solids conveyed through the second outlet duct 11 causes a density gradient in the second partial flow T ₂ as a result of the injection of the gaseous diluent V. Can be increased by. When the gaseous diluent V is injected through the device 15 (the lance 16 in the illustrated exemplary embodiment), the density of gas / solid mixture (and it) in the second partial stream T ₂ specific gravity also) by is reduced as compared with the first part stream T _1. This means that the result of the second partial stream T ₂ flows more quickly through the second outlet duct 11, solid amount carried by the second partial stream T ₂ is increased. The quantity ratio of the two partial streams T ₁ , T ₂ is to produce a desired density gradient in the second partial stream T ₂ , in other words to supply a desired amount of gaseous diluent. Can be effectively adjusted by. The radial orifice 17 forms an angle α of 0 ° to 45 ° with the horizontal axis plane h of the lance 16 and is disposed in the lower half of the lance wall so that solid particulates pass through the orifice 17 to the lance 16. An optimal distribution of the gaseous diluent is ensured without the risk of passing through and clogging the latter.
[0010]
The condition in the turning space 4 can be influenced if necessary by dividing the air chamber 7 into three zones into which the gaseous fluidizing agent is introduced separately.
[0011]
The device 1 Figures 1 illustrated in 3 is designed so that only makes it possible to further transported by all of the solid material the first part stream T ₁ to the required. The fact that the two turning edges 12, 13 are arranged at different heights plays a role here. If the lance 16 is disabled, in other words, if the diluent V are not injected into the second partial stream T _2, in the gaseous fluidizing agent F alone exceeds the higher turning edge 13 the We can not release the solid, and all the solid material is further conveyed by the first part stream T _1.
[0012]
The process according to the invention and the device according to the invention are used, for example, in the splitting of an incoming stream consisting of hot solid particles discharged from a fluidized bed reactor and separated from a smoke-gas stream into two partial streams in a cyclone. Can. One partial stream recycles the solid particles directly into the fluidized bed. The solid particles conveyed by the other partial stream are led back to the fluidized bed via a heat exchanger, preferably a moving bed cooler. Such recirculation of solid particles released from the fluidized bed is described, for example, in US Pat. No. 5,797,366. The adjustment according to the invention of the solids flow diverted through the moving bed cooler and cooled in the latter to recover heat effectively adjusts the temperature in the fluidized bed reactor or the flow It makes it possible to compensate for temperature fluctuations in the bed reactor. In the process known from the publications mentioned above, limestone, sand and other materials, for example in particulate form, are used as solid material for the fluidized bed. The solid material for the fluidized bed may also include fly ash or concentrated salt.
[0013]
Instead of a single lance, two or more lances can also traverse horizontally through the outlet duct. For example, it is also conceivable to place the lance in two horizontal planes, one above the other. Instead of being introduced via a lance, the gaseous diluent can be introduced via orifices which open radially into the outlet duct and are regularly distributed in the circumferential direction.
[0014]
The process according to the invention is simple and still makes it possible to precisely adjust the quantity ratio in the individual partial streams. An apparatus according to the invention for carrying out the method is cost effective from a manufacturing and maintenance point of view.
[Brief description of the drawings]
FIG. 1 is a vertical partial cross-sectional view of an exemplary embodiment of an apparatus for splitting an incoming stream of distributed solid particles into a partial stream.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1;
FIG. 4 is a longitudinal cross-sectional view of an exemplary embodiment of an apparatus for injecting a gaseous diluent into one of the partial streams.
FIG. 5 is a cross-sectional view taken along line VV in FIG. 4;

Claims (11)

A method for dividing into portions stream comprising the solid fine particles having inlet stream comprising solid particles previously controlled amount ratios _{(Z) (T 1, T} 2), wherein the inflow (Z) solid fine particles are fluidized, and is then deflected, is divided into partial streams (T _1, T _2), the amount ratio of the partial flow (T _1, T ₂₎ is at least one of the partial flows Is regulated by the density gradient generated in (T ₂ ), and one partial stream (T ₁ ) is recycled directly to the reactor and the other partial stream (T ₂ ) is passed through the heat exchanger to A method of splitting an incoming stream of solid particulates that is recycled to the reactor into partial streams. The method according to claim 1, wherein the density gradient of the one partial stream (T ₂ ) is generated by injection of a gaseous diluent (V). The inflow (Z) is guided downward from the top and fluidized in the bottom , and the divided partial flows (T ₁ , T ₂ ) are guided upward from the bottom. The method described. An apparatus for performing the method of claim 1, wherein the supply duct (3) for guiding flowing stream (Z) and the partial flow from the bottom upwards deflection space from the top (4) (T _1, T ₂ ) with outlet ducts (10, 11) for guiding , said turning space (4) having a bottom (5) with an orifice (6) for the injection of gaseous fluidizing agent (F) by an external and bounded, also at least one of a device for injecting gaseous diluent (V) (15), also an apparatus for injecting the gaseous diluent (V) of the derived duct (10, 11) (15) is formed by at least one tubular lance (16), said tubular lance (16) horizontally traversing the corresponding outlet duct (11) and the lower half of the lance in said outlet duct (11) ( a large number of radial cage to 16a) I comprising scan (17), the method of dividing the inflow stream comprising solid particles to the partial flow system. The device according to claim 4, wherein the axis (a) of the radial orifice (17) forms an angle (α) with the horizontal plane (h) of the lance (16). Device according to claim 4 or 5, wherein two orifices (17) are arranged symmetrically with respect to a vertical plane (v) of the lance (16) and on both sides thereof. The device according to claim 5 or 6, wherein the angle (α) is less than 45 °. Each derivation duct (10, 11) includes a vertical portion for guiding the partial flows upwardly from the turning space _{(4) (T 1, T} 2) (10a, 11a), the vertical portion (10a, 11a ) Including the portions (10b, 11b) for guiding the partial flows (T ₁ , T ₂ ) downward from the vertical direction (10a, 11a) and the portions (10b, 11b) 8. A device according to any one of claims 4 to 7 , wherein a turning edge (12, 13) is arranged on the surface. The turning edge (13) of the outlet duct (11) with the device (15) for injecting the gaseous diluent is more flowable than the turning edge (12) of the other outlet duct (10). 9. The device according to claim 8, which is arranged downstream . The diameter of the outlet duct (11) provided with the device (15) for injecting the gaseous diluent (V) is smaller than the diameter of the other outlet duct (10). The apparatus according to one item. Device according to one of the claims 4 to 10, comprising two outlet ducts (10, 11) exiting perpendicularly from the turning space (4) .

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